Oaky Creek erosion project first in a line of land remediation works.
Nearly one year ago Severe Tropical Cyclone Debbie crossed the coast bringing with it destructive winds up to 260km/hr and record rainfall along the Central coast.
There was widespread damage throughout the region to infrastructure, water courses and crops. Across Queensland, the estimated damage to cane and other crops was $270 million.
Locally, significant rainfall in the region resulted in substantial erosion along the creeks and rivers, the loss of many hectares of productive land, and tens of thousands of tonnes of sediment washing out to the Great Barrier Reef lagoon.
Seeing the need to support landholders, CANEGROWERS Mackay partnered with Reef Catchments and the Whitsunday Rivers Improvement Trust to fund an assessment of the impact caused by the cyclone to the regions waterways.
The assessment (undertaken by Alluvium Consulting) included a week of in-field surveys and site inspections. It identified a number of significantly impacted sites and creek lines throughout the Mackay Whitsunday region. This helped Reef Catchments secure funding under Natural Disaster Relief and Recovery Arrangements (NDRRA) Category D, jointly funded by both State and Federal Governments. The application was successful for both Stage 1 ‘urgent’ and Stage 2 activities.
Now, Reef Catchments is working with landholders to undertake a number of much needed remediation projects.
One creek significantly impacted was Oaky Creek, a tributary of Sandy Creek 20 kilometres south-west of Mackay. The creek experienced extremely high rates of channel migration, which threaten assets including farmland, roads, the irrigation scheme and electricity poles. Significant volumes of cobbles were deposited within the channel and through the floodplains. Left unaddressed there is the potential of a meander cut off, which will cut straight through a cane paddock.
To remediate the creek, Reef Catchments has again engaged Alluvium Consulting to develop a creek stability assessment and implementation plan. The stability assessment is broken into three stages:
1) Project Inception – learn the history of Oaky Creek / identify major issues of the stakeholders / identify management objectives
2) System Understanding – assess changes to channel / assess bed and bank stability and flood characteristics / predict future changes to the creek
3) Waterway restoration plan – Develop a range of management options / discuss options with stakeholders / develop a program of works
Early February (Tuesday 6th ) saw the first of three community consultation meetings organised by Reef Catchments to assist in developing the stability assessment. Stakeholders attending the meeting included: landholders from the creek, CANEGROWERS Mackay, Mackay Regional Council, Ergon, Sunwater, and the Department of Agriculture and Fisheries.
The assessment is expected to be completed by the middle of April and will outline a plan to remediate and stabilise the creek, including prioritisation of sites.
Alluvium Consulting will be using the latest technologies and skills to develop the plan including the creating a Digital Elevation Model of Difference and 2-dimensional Hydraulic modelling. However, involved landholders are key to understanding the systems and how events impact on the creek.
Works to be undertaken are expected to be completed by the end of 2018 and will include a range of stabilisation options such as rock toes and revegetation.